What HD is saying is if you know you won't be able to do 160kts to 4, then tell us before we give you the instruction (i.e. whilst downwind so that we can build in some extra room). If you only mention it once you're on final and you can't fly the speed, then you either fly the speed or we break you off the approach and start again. We are quite happy to accomodate people as long as they inform us in good time.